UndoManager.hpp Example File

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    #ifndef UNDOMANAGER_HPP
    #define UNDOMANAGER_HPP

    #include <QObject>
    #include <bb/cascades/Control>

    class QUndoStack;

    /**
     * The UndoManager wraps an instance of QUndoStack and makes its state available
     * via properties so that we can access them within the UI.
     */
    class UndoManager : public QObject
    {
        Q_OBJECT

        // These properties define whether there are commands on the stack that can be undone or re-done
        Q_PROPERTY(bool canRedo READ canRedo NOTIFY canRedoChanged)
        Q_PROPERTY(bool canUndo READ canUndo NOTIFY canUndoChanged)

        // These properties provide the text for the undo and redo button
        Q_PROPERTY(QString redoText READ redoText NOTIFY redoTextChanged)
        Q_PROPERTY(QString undoText READ undoText NOTIFY undoTextChanged)

    public:
        UndoManager(QObject *parent = 0);

        // The accessor methods for our properties
        bool canRedo() const;
        bool canUndo() const;
        QString redoText() const;
        QString undoText() const;

        /**
         * This method is called by the UI whenever the user has moved a Stone.
         * As a result it will push a new MoveCommand on the internal QUndoStack.
         */
        Q_INVOKABLE void createMoveCommand(bb::cascades::Control *control, int sourceX, int sourceY, int targetX, int targetY);

    public Q_SLOTS:
        /**
         * This method is called by the UI whenever the user presses the 'Redo' button
         */
        void redo();

        /**
         * This method is called by the UI whenever the user presses the 'Undo' button
         */
        void undo();

    Q_SIGNALS:
        // The change notification signals for our properties
        void canRedoChanged();
        void canUndoChanged();
        void redoTextChanged();
        void undoTextChanged();

    private:
        // The wrapped QUndoStack instance
        QUndoStack *m_undoStack;
    };

    #endif